Drop on demand ink jet technology is widely used in the printing industry. Printers using drop on demand ink jet technology can use either thermal ink jet technology or piezoelectric technology. Even though they are more expensive to manufacture than thermal ink jets, piezoelectric ink jets are generally favored, for example because they can use a wider variety of inks.
Piezoelectric ink jet print heads include an array of piezoelectric elements (i.e., transducers or PZTs). One process to form the array can include detachably bonding a blanket piezoelectric layer to a transfer carrier with an adhesive, and dicing the blanket piezoelectric layer to form a plurality of individual piezoelectric elements. A plurality of dicing saw passes can be used to remove all the piezoelectric material between adjacent piezoelectric elements to provide the correct spacing between each piezoelectric element.
Piezoelectric ink jet print heads can typically further include a flexible diaphragm to which the array of piezoelectric elements is attached. When a voltage is applied to a piezoelectric element, typically through electrical connection with an electrode electrically coupled to a power source, the piezoelectric element actuates to bend or deflect. Piezoelectric element actuation causes the diaphragm to flex which, in turn, results in a pressure pulse within an ink chamber and ejection of a quantity of ink from a chamber through one of a plurality of nozzles (i.e., nozzle aperture or nozzle opening) within a nozzle plate (i.e., aperture plate), for example a stainless steel nozzle plate, during printing. The flexing further draws ink into the chamber from a main ink reservoir through an opening to replace the expelled ink.
The use of a pressure wave to eject ink from a nozzle may result in various problems. For example, the pressure wave may propagate through ink supply channels, and may also create acoustic energy that is transmitted through solid printhead structures to result in crosstalk of the pressure pulse or acoustic energy to an adjacent nozzle. Other time-dependent effects may also result from acoustic energy, such as variation in jetting performance during a train of ejected ink droplets during printing. Pressure fluctuations resulting from the pressure pulse during ejection of one ink drop can affect drop ejection of subsequent drops, and may cause variations in drop volume, drop speed, and drop directionality. The printhead may be designed to decrease crosstalk and other adverse effects by attenuating the pressure wave. For example, rather than using a nozzle plate manufactured from stainless steel, the nozzle plate may be manufactured from a compliant material such as a polymer that dampens or attenuates the pressure wave by an amount that decreases crosstalk but still generates a sufficient pressure wave for printing from a desired nozzle.